1. Field of the Invention
The present invention concerns an improved spool for a two-spool tape cartridge in which a flexible, elastic drive belt contacts the tape on the tape spools and whereby movement of the belt causes movement of the tape between the spools.
2. Description of the Prior Art
The belt driven tape cartridge of U.S. Pat. No. 3,692,255, issued to Von Behren and assigned to the assignee of the present invention, has been very successfully utilized to interface with computers where rapid acceleration and deceleration of the tape are required. In the cartridge there disclosed, a magnetic recording tape is convolutely wound on two tape spools and is bidirectionally driven between the spools by an endless flexible belt in frictional contact with the tape on both spools.
When the cartridge of the Von Behren patent was first marketed in 1972, its magnetic recording tape had a width of 1/4 inch (6.35 mm), a thickness of 1 mil (0.025 mm), and was driven at 30 inches (762 mm) per second. Data were originally recorded on the tape at a density of 1600 flux reversals per inch (63 per mm). Current cartridges come in a variety of sizes and the recording tapes range in width from 0.150 inches (3.81 mm) to 0.250 inches (6.35 mm), may be as thin as 0.6 mil (0.015 mm), may be driven at 90 or more inches (2286 mm) per second, and data is recorded at densities of 10,000 flux reversals per inch (394 per mm) or more. In addition, data are recorded on a plurality of independent, parallel tracks, which may number in excess of 32, spaced across the width of the magnetic recording tape.
Although no problems were encountered when the cartridge was first introduced, the higher tape speeds, recording densities, and track densities have created a need for improved spool positioning during winding and unwinding of the magnetic tape.